| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Abdallah, J, et al.
(författare)
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Photon events with missing energy in e(+)e(-) collisions at root s=130 to 209 GeV
- 2005
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 38:4, s. 395-411
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Tidskriftsartikel (refereegranskat)abstract
- The production of single- and multi-photon events has been studied in the reaction e(+) e(-) --> gamma(gamma) + invisible particles. The data collected with the DELPHI detector during the years 1999 and 2000 at centre-of-mass energies between 191 GeV and 209 GeV was combined with earlier data to search for phenomena beyond the Standard Model. The measured number of light neutrino families was consistent with three and the absence of an excess of events beyond that predicted by the Standard Model processes was used to set limits on new physics. Both model-independent searches and searches for new processes predicted by supersymmetric and extra-dimensional models have been made. Limits on new non-standard model interactions between neutrinos and electrons were also determined.
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| 3. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 4. |
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| 5. |
- Brokelman, Walter J A, et al.
(författare)
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Peritoneal transforming growth factor beta-1 expression during laparoscopic surgery: a clinical trial.
- 2007
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Ingår i: Surgical endoscopy. - : Springer Science and Business Media LLC. - 1432-2218 .- 0930-2794. ; 21:9, s. 1537-41
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transforming growth factor-beta 1 (TGF-beta1) is a growth factor involved in various biologic processes, including peritoneal wound healing and dissemination of malignancies. Laparoscopic surgery is evolving rapidly, and indications are increasing. The peritoneal TGF-beta1 expression during laparoscopic surgery is unknown. METHODS: For this study, 50 patients scheduled for laparoscopic cholecystectomy were randomized into five groups, then surgically treated with various pressures, light intensities, and dissection devices. Peritoneal biopsies were taken at the beginning and end of surgery. Tissue concentrations of total and active TGF-beta1 were measured using enzyme-linked immunosorbent assay (ELISA) techniques. RESULTS: There was no significant difference in either total or active TGF-beta1 concentration between peritoneal biopsies taken at the start of surgery and samples taken at the end of the procedure. Patients who underwent surgery with the ultrasonic scalpel had significant lower levels of both active (p < 0.005) and total (p < 0.01) TGF-beta1 at the end of surgery than patients treated with electrocautery. Patients who had surgery with a high light intensity had significantly lower levels of total TGF-beta1 levels (p < 0.005) with an unchanged active part than patients who had surgery with low light intensity. CONCLUSION: The choice of dissection device and the light intensity used in laparoscopic surgery affect peritoneal TGF-beta1 concentrations, indicating that peritoneal biology can be affected by laparoscopic surgery. Because TGF-beta1 is involved in various biologic processes in the peritoneal cavity, this observation may have important clinical consequences.
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| 6. |
- Lindblad-Toh, Kerstin, et al.
(författare)
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Genome sequence, comparative analysis and haplotype structure of the domestic dog.
- 2005
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 438:7069, s. 803-19
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Tidskriftsartikel (refereegranskat)abstract
- Here we report a high-quality draft genome sequence of the domestic dog (Canis familiaris), together with a dense map of single nucleotide polymorphisms (SNPs) across breeds. The dog is of particular interest because it provides important evolutionary information and because existing breeds show great phenotypic diversity for morphological, physiological and behavioural traits. We use sequence comparison with the primate and rodent lineages to shed light on the structure and evolution of genomes and genes. Notably, the majority of the most highly conserved non-coding sequences in mammalian genomes are clustered near a small subset of genes with important roles in development. Analysis of SNPs reveals long-range haplotypes across the entire dog genome, and defines the nature of genetic diversity within and across breeds. The current SNP map now makes it possible for genome-wide association studies to identify genes responsible for diseases and traits, with important consequences for human and companion animal health.
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| 7. |
- Pocock, Tessa, et al.
(författare)
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Excitation pressure regulates the activation energy for recombination events in the photosystem II reaction centres of Chlamydomonas reinhardtii
- 2007
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Ingår i: Biochemistry and Cell Biology. - 0829-8211 .- 1208-6002. ; 85:6, s. 721-729
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Tidskriftsartikel (refereegranskat)abstract
- Using in vivo thermoluminescence, we examined the effects of growth irradiance and growth temperature on charge recombination events in photosystem IT reaction centres of the model green alga Chlamydomonas reinhardtii. We report that growth at increasing irradiance at either 29 or 15 degrees C resulted in comparable downward shifts in the temperature peak maxima (T-M) for S(2)Q(B)(-) charge pair recombination events, with minimal changes in S(2)Q(A)(-) recombination events. This indicates that such growth conditions decrease the activation energy required for S(2)QB(-) charge pair recombination events with no concomitant change in the activation energy for S(2)Q(A)(-) recombination events. This resulted in a decrease in the Delta T-M between S(2)Q(A)(-) and S(2)Q(B)(-) recombination events, which was reversible when shifting cells from low to high irradiance and back to low irradiance at 29 degrees C. We interpret these results to indicate that the redox potential of Q(B) was modulated independently of Q(A), which consequently narrowed the redox potential gap between Q(A) and Q(B) in photosystem II reaction centres. Since a decrease in the Delta T-M between S(2)Q(A)(-) and S(2)Q(B)(-) recombination events correlated with growth at increasing excitation pressure, we conclude that acclimation to growth under high excitation pressure narrows the redox potential gap between Q(A) and Q(B) in photosystem 11 reaction centres, enhancing the probability for reaction center quenching in C. reinhardtii. We discuss the molecular basis for the modulation of the redox state of Q(B), and suggest that the potential for reaction center quenching complements antenna quenching via the xanthophyll cycle in the photoprotection of C. reinhardtii from excess light.
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| 8. |
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| 9. |
- Brokelman, Walter J A, et al.
(författare)
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Decreased peritoneal tissue plasminogen activator during prolonged laparoscopic surgery.
- 2009
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Ingår i: The Journal of surgical research. - : Elsevier BV. - 1095-8673 .- 0022-4804. ; 151:1, s. 89-93
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Peritoneal fibrinolysis is crucial in the peritoneal healing processes and subsequent adhesion formation. During conventional surgery, the peritoneal fibrinolytic system is rapidly disturbed. Short-term laparoscopy does not seem to affect peritoneal fibrinolysis. The aim of the present study was to assess the effect of prolonged laparoscopic surgery on peritoneal fibrinolysis. METHODS: Twelve consecutive patients undergoing laparoscopic gastric bypass surgery for morbid obesity were included in the study. During the procedure, biopsies of the parietal peritoneum were taken at the start of the procedure and each 45 min afterward. Tissue samples were homogenized and tissue-type plasminogen activator (tPA) antigen, tPA activity, urokinase-type PA antigen, and plasminogen activating inhibitors type 1 antigen were measured using commercial assay techniques. RESULTS: Both tPA antigen and its activity progressively decreased during the procedure, reaching significant levels after 90 min of surgery. The levels of uPA antigen and plasminogen activating inhibitors antigen did not significantly change throughout the procedure. CONCLUSIONS: As for conventional surgery, prolonged laparoscopic surgery causes a decreased fibrinolytic activity in the peritoneum due to decreased tPA levels.
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| 10. |
- Brokelman, Walter J A, et al.
(författare)
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Peritoneal fibrinolytic response to various aspects of laparoscopic surgery: a randomized trial.
- 2006
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Ingår i: The Journal of surgical research. - : Elsevier BV. - 0022-4804. ; 136:2, s. 309-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Peritoneal fibrinolysis is important in peritoneal wound healing processes and adhesion formation. The peritoneal fibrinolytic response to laparoscopy is merely unknown. In the present study we investigate the effect of short-term laparoscopy on the peritoneal fibrinolytic response and the influence of intra-abdominal pressure, light intensity and choice of dissection device on this response. METHODS: There were 50 patients scheduled for laparoscopic cholecystectomy randomized in five groups operated with various pressures, light intensities, and dissection devices. Peritoneal biopsies were taken at the beginning and the end of the procedure. Tissue concentrations of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor type 1 (PAI-1), and the tPA-activity were measured using ELISA techniques. RESULTS: There were no differences in tPA antigen, tPA-activity, uPA antigen, or PAI-1 antigen concentrations in biopsies taken at the beginning compared to samples taken at the end of the operation. Different intra-abdominal pressures, light intensities and the choice dissection device did not affect any of the measured parameters. CONCLUSION: Short-term laparoscopy does not affect the peritoneal fibrinolytic activity. The used intra-abdominal pressure, light intensity and choice of dissection device do not affect peritoneal activity during short-term laparoscopy.
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